I use phpMyAdmin to manage MySQL databases.
I think it is an excellent tool.
It's an easy way to centralize administration for databases on different servers using one single web interface.
Anyhow, the server running phpMyAdmin has to be granted access on a newly installed database.
This has to be done from the command line on the database server.
So, before any MySQL password has been set, just run the command below.
NOTE:
Typing as written below means that you press ENTER twice before the command is executed.
And don't forget to replace '***ADMIN***', '***REMOTE.SERVER.IP.ADDRESS***', and '***PASSWORD***' with your values...